In order to provide a modular headliner which may be snap-fit into the vehicle body structure, it is necessary to provide appropriate openings to allow the modular headliner to be installed while recognizing that part variances and tolerances, welding and other factors affect the vehicle part spacing and alignment during the assembly process. The typical structure to which the sunshades and headliner are mounted is an extending flange from the A-pillar inner (also known as windshield side inner) on either side of the front of the car. These two A-pillar inners are completely distinct sheet steel members. The spacing between openings formed one in each A-pillar is not necessarily consistent nor is the front to back spacing constant. A header (also known as a windshield inner upper) extends across the front of many vehicles above the terminal ends of the A-pillar inners and may be formed such that all the openings therein are stayed simultaneously such that the positioning between the openings therein is maintained constant. The problem is then to determine how to mount a modular headliner using a snap-fit engagement to the sheet metal of the body structure and still provide for finished vehicles having the headliner installed at the right location in alignment and otherwise be a world class product.
The herein described combination of openings, having a long dimension for allowing sliding movement of the fastener within the opening in one direction and having a shorter dimension for preventive sliding motion in the opposite direction has been found particularly useful with the fastener of the type shown. By providing a plurality of openings, it is possible to maintain the desired alignment of the headliner while allowing for a snap-fit arrangement. If a modular headliner was mounted only to A-pillar openings, then based upon the alignment of the openings in the A-pillar, the entire headliner might be skewed due to a minor variation in the relative positions of the openings, such as variations which usually occur during the assembly process.